1. Field of the Invention
The present invention relates to a cleaning device for use in an image forming apparatus such as an electrostatic copier, a laser printer, and a facsimile machine, and more particularly to a cleaning device for use in an image forming apparatus provided with an a-Si (amorphous silicon) photosensitive drum.
2. Description of the Related Art
There is known an mage forming apparatus e.g. a printer provided with an amorphous silicon photosensitive drum. Amorphous silicon to be used as a material for the amorphous silicon photosensitive drum has a relatively large hardness and a long useful life, but has a disadvantage that an electric charge is likely to leak during a long-term use. Accordingly, there is a likelihood that a toner image may be deteriorated in use of the amorphous silicon photosensitive drum. There is proposed a cleaning device equipped with a cleaning roller to prevent deterioration of a toner image. Specifically, the cleaning roller is constantly pressingly contacted against the surface of the photosensitive drum to thereby polish the surface of the photosensitive drum. The cleaning roller is made of a foaming synthetic rubber. A cleaning device with a cleaning roller is e.g. disclosed in Japanese Unexamined Patent Publication No. 2000-112309.
The cleaning device disclosed in the publication includes: a support shaft; a pair of arm members pivotally supported about the axis of the support shaft; a cleaning roller interlocked with an end of the arm member pair; a spring member for applying a load to the surface of an amorphous silicon photosensitive drum by way of the cleaning roller; a first gear integrally rotated with the photosensitive drum; and a second gear which is integrally rotated with the cleaning roller and in mesh with the first gear.
There is also known a cleaning device provided with a spiral roller for collecting toner particles. The cleaning device is advantageous in layout designing by engaging a gear of the spiral roller with a gear of a cleaning roller and by driving the spiral roller with use of the gear of the cleaning roller.
In the above arrangement, however, there is a likelihood that jitter of a photosensitive drum may cause image jitter or noise. In other words, in the arrangement of driving the spiral roller by the gear of the cleaning roller, the driving force of the cleaning roller may fluctuate, which may cause jitter of the photosensitive drum, thereby resulting in image jitter or noise.